Community Forums

FBL · 03-06-2021, 10:11 AM

I read conflicting posts and articles on this topic. Here is one from DIYSOLAR that really helped me.

. All chargers react to battery voltage. They can't see anything but battery voltage and the amps the battery is PULLING from the charger. If the charger sees the battery voltage hit absorption, it tapers current to hold it.
. The battery voltage is like a boat anchor. It's voltage will not rise above what the incoming current dictates. You could put a 100V/2A power supply on the battery, and the battery would pull the 100V down to the battery's voltage with 2A incoming.

Provided you are using SUITABLE chargers appropriately programmed for the target battery, you could charge simultaneously with, solar, wind, second solar controller, second wind, grid, hydro power, third solar controller, generator powering an AC charger, alternator, etc. Each charger would react to the battery voltage and lower the current to maintain it.

Multiple chargers only accelerate charging during the bulk phase. Once absorption is hit, typically only the highest current charger will continue to charge the battery as all others will have tapered their current to 0 in response to the absorption voltage and drop to float mode while the strongest finishes the charge.

R Cabesa · 03-06-2021, 11:46 AM

I have no idea if your statement about the 100V/2A charger is true or not but I would not consider that a SUITABLE charger.

I have FIVE chargers in my system. 3 solar charge controllers, 1 Battery to Battery, and one shore charger. They all are set for my house battery voltage and tail current per the battery manufacture's specs.

IF ALL were running full power I would be charging a little beyond the battery's max charging amps but the chance of that is slim. I can turn the battery to battery charger off from the drivers seat, (actually, rarely turn it on) the solar rarely hits its max, and I don't have enough cord to run the shore charger going down the road

That said, they all seem to react to the battery charged voltage and switch from bulk to absorb to float within a couple of hundreds of a volt and a few seconds of each other. Tapering down amps in the process.

astrocamper · 03-06-2021, 02:38 PM

I have four MPPT charge controllers and an Multiplus 3000VA inverter/charger. Even if all my solar and charger function for my inverter/charger were going at max rate I still wouldn't be over the recommended charge rate of 0.5C of my 700 amp-hours of BattleBorn LiFePO4 batteries.

I don't normally use the most of my capacity of my batteries in a 24 hour period. I have the additional batteries to help with snow over panels or cloudy weather or a few nights in heavily tree covered areas.

FBL · 03-07-2021, 02:57 PM

I am into Thoreau's "SIMPLIFY, SIMPLIFY, SIMPLIFY" ��

FBL · 03-07-2021, 03:07 PM

Quote:

Originally Posted by R Cabesa

I have no idea if your statement about the 100V/2A charger is true or not but I would not consider that a SUITABLE charger.

I have FIVE chargers in my system. 3 solar charge controllers, 1 Battery to Battery, and one shore charger. They all are set for my house battery voltage and tail current per the battery manufacture's specs.

IF ALL were running full power I would be charging a little beyond the battery's max charging amps but the chance of that is slim. I can turn the battery to battery charger off from the drivers seat, (actually, rarely turn it on) the solar rarely hits its max, and I don't have enough cord to run the shore charger going down the road

That said, they all seem to react to the battery charged voltage and switch from bulk to absorb to float within a couple of hundreds of a volt and a few seconds of each other. Tapering down amps in the process.

It was not my statement about the 2A charger, and the article goes on to say " if you are using a suitable charger", not that 2A was suitable. It was referring to something earlier in an article.
The topic, on which there are conflicting posts all over the RV forums, is whether there is ANY PROBLEM with using a solar panel while on shore power.
Both replies seemed to want to showcase over the top and work intensive arrays of chargers. I would rather take a walk in the woods.

jcussen · 03-07-2021, 03:55 PM

Quote:

Originally Posted by FBL

It was not my statement about the 2A charger, and the article goes on to say " if you are using a suitable charger", not that 2A was suitable. It was referring to something earlier in an article.
The topic, on which there are conflicting posts all over the RV forums, is whether there is ANY PROBLEM with using a solar panel while on shore power.
Both replies seemed to want to showcase over the top and work intensive arrays of chargers. I would rather take a walk in the woods.

No problem.

n0mad · 03-08-2021, 09:03 PM

Quote:

Originally Posted by FBL

Multiple chargers only accelerate charging during the bulk phase. Once absorption is hit, typically only the highest current charger will continue to charge the battery as all others will have tapered their current to 0 in response to the absorption voltage and drop to float mode while the strongest finishes the charge.

Victron DVCC will control multiple Victron-brand charging sources so they aren't making independent determinations. Other vendors probably have similar systems.

R Cabesa · 03-09-2021, 03:03 PM

Quote:

Originally Posted by FBL

It was not my statement about the 2A charger, and the article goes on to say " if you are using a suitable charger", not that 2A was suitable. It was referring to something earlier in an article.
The topic, on which there are conflicting posts all over the RV forums, is whether there is ANY PROBLEM with using a solar panel while on shore power.
Both replies seemed to want to showcase over the top and work intensive arrays of chargers. I would rather take a walk in the woods.

OK so the simple answer to your question is NO.

I'm not trying to showcase anything about my simple but redundant system. It all just works and I never have to worry about my system being up to what I ask of it. That way I can enjoy MY walk in the woods

p.s. I just added a FIFTH charger yesterday. This one charges my chassis battery from the House bank. Now I don't have to worry if the truck will start to get me to the trail head